// Copyright 2017 the V8 project authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef V8_WASM_LOCAL_DECL_ENCODER_H_
#define V8_WASM_LOCAL_DECL_ENCODER_H_

#include "src/globals.h"
#include "src/wasm/wasm-opcodes.h"
#include "src/zone/zone-containers.h"
#include "src/zone/zone.h"

namespace v8 {
namespace internal {
    namespace wasm {

        // A helper for encoding local declarations prepended to the body of a
        // function.
        class V8_EXPORT_PRIVATE LocalDeclEncoder {
        public:
            explicit LocalDeclEncoder(Zone* zone, FunctionSig* s = nullptr)
                : sig(s)
                , local_decls(zone)
                , total(0)
            {
            }

            // Prepend local declarations by creating a new buffer and copying data
            // over. The new buffer must be delete[]'d by the caller.
            void Prepend(Zone* zone, const byte** start, const byte** end) const;

            size_t Emit(byte* buffer) const;

            // Add locals declarations to this helper. Return the index of the newly added
            // local(s), with an optional adjustment for the parameters.
            uint32_t AddLocals(uint32_t count, ValueType type);

            size_t Size() const;

            bool has_sig() const { return sig != nullptr; }
            FunctionSig* get_sig() const { return sig; }
            void set_sig(FunctionSig* s) { sig = s; }

        private:
            FunctionSig* sig;
            ZoneVector<std::pair<uint32_t, ValueType>> local_decls;
            size_t total;
        };

    } // namespace wasm
} // namespace internal
} // namespace v8

#endif // V8_WASM_LOCAL_DECL_ENCODER_H_
